List of legendary creatures (K)
- Kabouter – Little people that live underground, in mushrooms, or as house spirits
- Kachina – Nature spirit
- Kahaku – Little people and water spirits
- Kajsa – Wind spirit
- Kalakeyas – Descendants of Kala
- Kallikantzaroi – Grotesque, malevolent spirit
- Kamaitachi – Wind spirit
- Kamatayan – Philippine counterpart of Death
- Kami – Nature spirit
- Kamikiri – Hair-cutting spirit
- Kanbari-nyūdō – Bathroom spirit
- Kangla Sha – Dragon Lion in the Kangla Palace
- Kanbo – Drought spirit
- Kanedama – Money spirit
- Kappa – Little people and water spirit
- Kapre – Malevolent tree spirit
- Karakoncolos, also in Bosnia and Herzegovina and Serbia known as Karanđoloz – Troublesome spirit
- Karakura – Male night-demon
- Karasu-tengu – Tengu with a bird's bill
- Karkadann – One-horned giant animal
- Karkinos – Giant crab
- Karura – Eagle-human hybrid
- Karzełek – Little people and mine spirits
- Kasa-obake – Animated parasol
- Kasha – Cat-like demon which descends from the sky and carries away corpses
- Kashanbo – Kappa who climb into the mountains for the winter
- Katawa-guruma – Woman riding on a flaming wheel
- Katsura-otoko – Handsome man from the Moon
- Katallan – Man-eating giant
- Kaukas – Nature spirit
- Kawa-uso – Supernatural river otter
- Kawa-zaru – Smelly, cowardly water spirit
- Kayeri - Mushroom-like monster
- Ke'lets – Ogre or evil spirit
- Keelut – Hairless dog
- Kee-wakw – Half-human half-animal cannibalistic giant
- Keibu Keioiba – Man with the body of a human but the head of a tiger
- Kekkai – Amorphous afterbirth spirit
- Kelpie – Malevolent water horse
- Ker – Female death spirit
- Kesaran-pasaran – Mysterious, white, fluffy creature
- Keukegen – Disease spirit
- Keythong – Wingless griffin
- Khalkotauroi – Bronze-hoofed bulls
- Khyah – Fat, hairy ape-like creature
- Kigatilik – Night-demon
- Kholomodumo – Gluttonous monster that was one of the first beasts of creation
- Kijimunaa – Tree sprite from Okinawa
- Kijo – She-devil
- Kikimora – Female house spirit
- Killmoulis – Ugly, mischievous mill spirit
- Kinnara – Human-bird hybrid
- Kin-u – Bird
- Kirin – Japanese Unicorn
- Kishi – Malevolent, two-faced seducer
- Kitsune – Fox spirit
- Kitsune-Tsuki – Person possessed by a fox spirit
- Kiyohime – Woman who transformed into a serpentine demon out of the rage of unrequited love
- Klabautermann – Ship spirit
- Knocker (folklore) – Little people and mine spirits
- Knucker – Water dragon
- Kobalos – Goblin like thieves and tricksters
- Kobold – Little people and mine or house spirits
- Kodama – Tree spirit
- Kofewalt – House spirit
- Ko-gok – Hideous monster
- Kokakuchō – Ubume bird
- Komainu – Protective animal
- Konaki-jiji – Infant that cries until it is picked up, then increases its weight and crushes its victim
- Konoha-tengu – Bird-like creature
- Konrul – Bird that is reborn
- Koro-pok-guru – Little people
- Korrigan – Little people and nature spirits
- Koshchei – Villainous figure that is unkillable, usually by hiding "his death" inside objects to protect it
- Koto-furunushi – Animated koto
- Kraken – Sea monster
- Krasnoludek – Little people nature spirits
- Krasue – Vampiric, floating head
- Krampus – Christmas Devil who punishes badly-behaved children
- Kting Voar – Snake eating cattle
- Kuarahy Jára – Forest spirit
- Kubikajiri – Female corpse-chewing graveyard spirit
- Kuchisake-onna – Vengeful ghost of a woman mutilated by her husband
- Kuda-gitsune – Miniature fox spirit
- Kudan – Human-faced calf which predicts a calamity before dying
- Kui – One-legged monster
- Kujata – Cosmic bull
- Kukudhi – Female demon who spreads sickness
- Kukwes – Large, hairy, greedy, human-eating bipedal monsters whose scream can kill
- Kulshedra – Drought-causing dragon
- Kumakatok – Death spirits
- Kumiho – Fox spirit
- Kun – Giant fish
- Kupua – Shapeshifting tricksters
- Kurabokko – Guardian spirit of a warehouse
- Kurage-no-hinotama – Jellyfish which floats through the air as a fireball
- Kurma – Second avatar of Vishnu in the form of a Turtle
- Kurupi – Wild man and fertility spirit
- Kushtaka – Shapeshifting "land otter man"
- Kye-ryong – Chicken-lizard hybrid
- Kyourinrin – Animated scroll or paper
- Kyūbi-no-kitsune – Nine-tailed fox
- Kyūketsuki – Vampire king